The use of an ultraviolet light source to kill bacteria and other microorganisms found in the air has been known for many years. In short, ultraviolet light is of a frequency which is able to effectively kill many types of microorganisms including bacteria and viruses. It is known to place ultraviolet light sources in an air stream in order to assist in the cleaning or sterilization of air introduced into a defined area. For example, it is known to place germicidal or ultraviolet lamps into the air stream of air handling units in order to clean and disinfect air which may be recirculated in an enclosed space. This cleaning or sterilization effect helps in reducing the contraction of bacterial or viral infections in closed air spaces such as offices which may not receive enough quantities of fresh air. Particularly in the winter months for colder climate areas, the introduction of fresh air into air handling units is greatly reduced in such colder months. Therefore, to alleviate the undue recirculation of contaminated air which may contain bacterial or viral agents, a complex set of filters along with ultraviolet lamps may be used.
One major problem with prior art devices which introduce a germicidal lamp directly into the air stream of an air handling unit is that the lamp receptacles which receive the lamps are not strong enough to withstand the continual bending stress created by high velocity air passing over the germicidal lamps. Accordingly, the bases of the lamps fracture or are otherwise damaged by the high velocity. The lamp receptacles themselves may also become damaged due to the continual stress. Over a period of time, the entire air sterilization device may need to be replaced because the lamp receptacles have been so damaged that they are no longer able to hold germicidal lamps.
Additionally, the high amount of dust and other particulate matter which passes through an air handling unit ultimately introduces these particles in the small gaps between the lamp receptacles and the base portions of the lamps. Because the lamps are not effectively sealed with respect to the lamp receptacles, the lamps often cannot be unscrewed from the receptacles which requires the entire sterilization device to be removed from the air handling unit.
Finally, germicidal lamps, like all bulbs or lamps, need replacement over time as they burn out. Germicidal lamps particularly need to be cleaned periodically to remove dust and particulate buildup which form on the lamps. If such buildup is not removed, the ability of the ultraviolet light to penetrate the oncoming air stream is greatly diminished. However, most prior art devices require one to access the air handling unit interior in order to remove the lamps which makes bulb cleaning and replacement difficult.